www.boxertrix.com

Start with the simple stuff.

Look for play in any joints/bearings from front to back of the bike.

Front.
Wheel Bearings
Ball Joints
Fork Bushes

Check the brakes aren't binding or anything odd.

Swingarm bearings
Paralever bearings
Final drive bearings.

Make a list and tik them off if you are happy with them, hopefully the culprit will make itself known. If none of this works it might be time to get the tape measure out.

Corvus wrote:

The Teutonic Tangerine wrote:Torque steer caused by crankshaft rotation = veering to the right

Is that a "steady state" phenomenon? ie: a steady amount of transmitted torque induces a certain amount of counter steer to cancel it. I'm struggling to see how that can be.

Isn't it more of an "instantaneous" phenomenon, in reaction to accelerating or decelerating the crank/clutch inertia mass?

It seems to be just as violent on the stand, in neutral, in reaction to a blip of the throttle. In that example there is zero transmitted torque, yet the reaction is very noticeable.

I just know that if you are riding with open throttle and then let the throttle go as well as the handlebars the bike will veer to the right but as the revs die down the effect is much less. Not sure what you means by the second part "Zero Transmitted Torque". If the crankshaft is spinning it is creating torque. The best way to feel it is to stand astride the bike so that you are keeping it upright by the use of your thighs then blip the throttle you will feel the whole bike trying to fall over to the right this is as a result of the forces set up by the spinning crank and it is this force which I believe causes the bikes to veer to the right (My R1200ST also does the same thing as did my old Air Head R80RT.

The Teutonic Tangerine wrote:

Corvus wrote:

The Teutonic Tangerine wrote:Torque steer caused by crankshaft rotation = veering to the right

Is that a "steady state" phenomenon? ie: a steady amount of transmitted torque induces a certain amount of counter steer to cancel it. I'm struggling to see how that can be.

Isn't it more of an "instantaneous" phenomenon, in reaction to accelerating or decelerating the crank/clutch inertia mass?

It seems to be just as violent on the stand, in neutral, in reaction to a blip of the throttle. In that example there is zero transmitted torque, yet the reaction is very noticeable.

I just know that if you are riding with open throttle and then let the throttle go as well as the handlebars the bike will veer to the right but as the revs die down the effect is much less. Not sure what you means by the second part "Zero Transmitted Torque". If the crankshaft is spinning it is creating torque. The best way to feel it is to stand astride the bike so that you are keeping it upright by the use of your thighs then blip the throttle you will feel the whole bike trying to fall over to the right this is as a result of the forces set up by the spinning crank and it is this force which I believe causes the bikes to veer to the right (My R1200ST also does the same thing as did my old Air Head R80RT.

What I meant by transmitted torque is any torque required to propel the vehicle. I didn't realise that holding the throttle to give a steady state amount of torque to propel the bike would need a certain amount of countersteer to hold a straight line. My understanding was that this "torque reaction" was actually a reaction only to the rapid acceleration or deceleration of the crank/clutch assembly. ie: a relatively short lived event.

Ps: above assumes that one actually believes in countersteer in the first place!

I do.

The Teutonic Tangerine wrote:I just know that if you are riding with open throttle and then let the throttle go as well as the handlebars the bike will veer to the right but as the revs die down the effect is much less.

But what if, just before you take your hands off the bars, you put it into neutral and switch off the engine.
What if it still veers to the right then.
Not that I'd be inclined to try it.
I've got more important things to occupy my thoughts with

bikesnbones wrote:

The Teutonic Tangerine wrote:I just know that if you are riding with open throttle and then let the throttle go as well as the handlebars the bike will veer to the right but as the revs die down the effect is much less.

But what if, just before you take your hands off the bars, you put it into neutral and switch off the engine.
What if it still veers to the right then.
Not that I'd be inclined to try it.
I've got more important things to occupy my thoughts with

I see your line of thought. Impeccable logic spoiled by practical and safety issues in the field! Shame.

Does the bike want to lean at a constant engine speed when stationary in neutral and off the stand?

slparry wrote:

er-minio wrote: Steering plate? What's that then?

THIS:

As I wrote a few posts back, the bike now goes straight.
Done a trackday yesterday at Snetterton and handled beautifully.

If none of this works it might be time to get the tape measure out.

Yes! Over the last month, sort of went through your checklist (bearings, etc.) and at the end... laser wheel alignment solved it all

Thanks!

PS
this is not my first boxer bike... and I would say I am pretty accustomed to all the quirks of BMW bikes, torque steer, etc. etc.
If I say the bike tends to go on one side, it means it tends to go to that side A LOT...

The top Yoke/forks were twisted!

That'll do it.

Glad you got it sorted.

conkerman wrote:The top Yoke/forks were twisted!

Yep, that's what I was trying to say with "steering plate" (literal translation from the italian term for it)

er-minio wrote:As I wrote a few posts back, the bike now goes straight.
Done a trackday yesterday at Snetterton and handled beautifully.

If none of this works it might be time to get the tape measure out.

Yes! Over the last month, sort of went through your checklist (bearings, etc.) and at the end... laser wheel alignment solved it all

Thanks!

PS
this is not my first boxer bike... and I would say I am pretty accustomed to all the quirks of BMW bikes, torque steer, etc. etc.
If I say the bike tends to go on one side, it means it tends to go to that side A LOT...

Glad it got sorted.

So. This torque steer thing. Take me through it chaps......

Is it what I said or not? Steering usually coincides with the need to shut off and open back up the throttle, thus accelerating and decelerating the crank/clutch mass. If I am right then use of the word "torque" is confusing as it gives the impression that somehow the transmitted torque is the cause. Which, if I'm wrong, it may be!

If someone can come up with a definitive explanation I suggest it should get pinned, along with all the other perennial boxer quirks questions.

You can feel the torque reaction when blipping the throttle, not convinced it has that great an effect when moving though, perhaps really slowly I guess but at higher speeds I'd have thought the mass of the bike moving forward would over come it?

The reaction is related to acceleration.

Hold a steady rev with the bike off the stand. Does it pull to the side??

slparry wrote:You can feel the torque reaction when blipping the throttle, not convinced it has that great an effect when moving though, perhaps really slowly I guess but at higher speeds I'd have thought the mass of the bike moving forward would over come it?

Yes, but what is it?

I can certainly feel it if I give a good ole blip o the throttle as I'm changing down. But, as I've been saying, for that moment in time, with the clutch pulled in, there is no transmitted torque.